In U.S. Pat. No. 1,929,174, issued Oct. 3, 1933 to George Lasco, there is shown a brake pipe angle cock having a tapered-type cock key that is provided with a longitudinally disposed tapered groove on its larger end which groove, in the closed position of the key, establishes a communication between the interior of an air brake hose connected to the outlet end of the angle cock body and atmosphere via this groove and a bore that extends through the cock body from the wall surface of a tapered bore in the body in which the tapered-type key is rotatably mounted to the exterior surface of this body. Thus, the fluid under pressure in the air brake hose is vented to atmosphere via this communication when the cock key is rotated to a closed position in which communication between the interior of the brake pipe and the interior of the hose is cut off.
In U.S. Pat. No. 3,498,585, issued Mar. 3, 1970 to Fred Temple et al, and assigned to the assignee of the present invention, there is shown a ball-type angle cock that constitutes a part of the freight car brake apparatus provided on the majority of freight cars owned and operated by American railroads.
Many American railroads on certain of their freight cars require an angle cock that, when in its closed position, establishes a communication between the interior of the air brake hose connected to the outlet end of the angle cock body and atmosphere. However, the ball-type angle cock disclosed in the above-mentioned U.S. Pat. No. 3,498,585, is not provided with such a communication between the interior of the air brake hose and atmosphere.
Accordingly, it is the general purpose of this invention to provide a ball-type angle cock having novel means for venting fluid under pressure from the interior of an air brake hose connected to the outlet of such an angle cock upon turning the handle of the angle cock to its closed position in which communication between the brake pipe and the interior of this air brake hose is closed.